UBS and Deutsche Bank questioned over 'dark pool' trading

Two more banks – UBS and Deutsche Bank – have been drawn in to the controversy over "dark pools", the private trading systems recently highlighted by bestselling author Michael Lewis in his latest book on Wall Street.

UBS disclosed that it was responding to inquiries about the use of its dark pool from a number of regulators including the Swiss domestic regulator, as well as the Securities and Exchange Commission in the US and the New York attorney general. Deutsche Bank also revealed that had been asked for information.

Dark pool exchanges are operated by banks and allow dealers to remain anonymous until their trades are executed. Lewis argues they are used by high frequency traders who try to make profits by trading faster then everyone else.